Apparatus for producing gas



2 Sheets-Sheet 1 /af// II/ v N. F. PRATT Filed Sept. 25, 1950 APPARATUS FOR PRODUCING GAS Aug. 1s, 1936.

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1r. mlm r gp.. ,F n a m m Aug. 1 8, 1936. N F, PRATT 2,051,743

APPARATUS FOR PRODUCING GAS Filed Sept'. 25, 1930 n I 2 Sheets-shet 2 I I A y l A l 57 I 56 6.9 63

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WMM" l Patented ug. 1:8, 12936Q UNITED STATES- PATENT OFFICE 4 Claims'.

This invention relates to structure and process for vaporizing hydro-carbon oils and other liquid fuels and other liquids in such a way that neither the liquids which are vaporized nor the 5 vapors formed from them are broken down or changed chemically in any way and is to avoid the formation of carbon when vaporizing hydrocarbon oils for the purpose of supplying these .vapors formed to substitute for fuel gas; in this connection an intermediate liquid whose boiling point is above that of water is used.

The prime object is to obtain Voil-vapor for use `from hydro-carbon oil by the quickest and most eicient means, wherein the fuel gradually i5 Vvaporizes as it ascends in heat-interchangers and avoids ebullition which would impair the efficiency of the heating apparatus. Heretofore, where hydro-carbon oils are subjected to sudden heat, ebullition takes place which results in a mixture of vapor and liquid instead of a solid column of dry vapor, which is highly desirable for eflicient burning, equalling or surpassing the Yresult obtained from fuel gas. In my invention theoil is vaporized and held in a vaporous state until used, the range of temperature being above that of the dry point of the oil but below `the cracking point of the Vapor, the vapor having the qualities (in this range of temperature) of a mixture of xed gases and throughout the specication is referred to as a gas.

Another object is to provide a series of heat- Y ing elements, made of different metals, each having a different heat conductivity, whereby an element of quick conductivity can be used to start the vaporizing operation and one of slower conductivity utilized after the vaporizing operation is under way.

Another object is to utilize a substance (liquid) having its boiling point higher than that of water 40 but below the cracking point of the hydro-carbon being vaporized, sothat this high lboiling liquid may be -rst vaporized by aprirne heating element and itsVapor brought through a heatinterchanger to in turn vaporize the hydro-carbon oil. `The liquid has therefore a 4high boiling point and at a low and safe pressure has a temperature above the dry point of the oil but below the cracking point of the gas formed from the hydro-carbon. The vapor from the liquid is made to pass downward through a super-heater and heat-interchangers; through an adjacent passage the hydro-carbon and gas resulting therefrom are passed upward in the opposite direction.

,55 In'this way the gas from Ythe hydro-carbon is formed without ebullition and super-heated to a point just below its cracking point. It is mpossible to form carbon under this process as the vapor from the intermediate liquid never reaches the temperature at which the oil-gas begins towv 5 crack but is always at a temperature above the dry point of the hydro-carbon being vaporized as it cornes in contact with the walls of the superheater and heat-interchanger, so that, as it passes downward it gradually gives off its heat 1.0 to the rising hydro-carbon and gas and condenses Where it gives off its latent heat and passes by gravity back to the boiler Where it is re-vaporized torepeat the cycle.

, Still another object is to do away with any l5 other pressure than that resulting from gravity in the use Q f this apparatus. Since gas formed from the oil -is so rich that at the common pressures of fuel-gas, it does not exert suflicient drag to pull in enough ,fresh air .for Complete Combusv.zo tion (blue-flame) means must be provided to dilute this rich oil-gas with air or some other gas or vapor so that the resultant gasstream will approximate the heat value of ordinary fuel gas at the ordinary and common pressure and Win25 `have the same heat valuefper cubic foot and exert the same pull in properly designed air-mixing devices. My arrangement makes possible the use of this apparatus without subjecting the oil to other than pressure produced by gravity. 30

Another object is to place in the system a massof cheap metal which has slow conducitivity but great thermal capacity. 'Ihis mass is so proportioned that it ordinarily absorbs heat from chemical vapor or a heating element, so. that 35 the heat above the boiling point of the fuel and below the cracking pointof the lgas is sufficient in heat units to supply heat to vaporize fresh fuel until the chemical boiler can start delivering heat to a thin walled vaporizer or a vaporizer of great- 40 ler conductivity and lessthermal capacity.

Y Otherr objects will be disclosed in the specification and Vclaims forming a part of this application. In the drawings: y Figure 1 is a diagrannnatic vertical section of the system showing the parts in relationto each other;

Figure 2 kis a horizo-ntal section taken on line 2--2 of Figure 1 l Figure 3 is a detailed section taken on line 3 3 of Figure 1; Y Y Figure 4 is a vertical section of the valve shown in Figure 3, taken on line 4--4 of Figure 1;

Figure 5 is a detailed view in section of a 55 valve forming a part of the apparatus shown in Figure l;

Figure 6 is a section on line 6-6 of Figure 5.

Figur-e 7 is an irregular section taken on line 1-1 of Figure 5;

Figure 8 is a section taken on line 8--8 of Figure 5; and

Figure 9 is a horizontal section taken on line 9-9 Figure 8.

Referring to the drawings in which like parts are designated with similar numerals:

Numeral I4 designates a boiler in which isV placed a chemical, such as di-phenyl-oxide or other chemicals whose boiling points are higher than that of water but lower than the cracking points of the hydro-carbon oils or other liquids being vaporized or of the vapors produced from these particular liquids.

Such chemicals will not break down under the direct application of heat as applied to the boiler but will give off vapors which have relatively high temperatures and relatively low pressures.. Beheath the boiler I4 is placed a source of heat i5. Extending from the boiler I4 is a duct I6 which passes through a vapor dryer I1, and in turn to other vaporizers (heat interchangers) i8, I9, 25 and 2i. It is to be noted that the vapor dryer I1 is inclined so that any condensation passes back to the boiler lI4 by way of vaporizers I 3, i5, 2G and 2i and away from duct I5, thus making it possible to retain all of the chemical vapors heat Vfor purposes of heating the oil and oil-gas in the dryerrand vaporizers. Extending from duct I5 is a duct 422 in the form of a header from which extend ducts `23 and 24 into vaporizer I9, duct 25 into vaporizer ,20, and ducts 25 and 21 into vaporizer l2I. The vapor dryer l1 is connected to the vaporizers I8, I9, 20, and 2l by ducts 28, 29, 35, and SlI. Partial check valves 32, 33, 34, and 35 are placed in ducts 28, 29, 3Q and 3| respectively. Return vapor ducts 34a, 35a, 36, 31, S'and 39 connect with header pipe 48 which connects with lower partlof boiler i4. A reservoir 4i containing hydro-carbonvoil or other liquid to be vaporized without cracking, is placed in such a manner that its top or overflow is below top of lowest vaporizerbut :high enough to Vassure passage by gravity of the liquid through the system. Extending fromthe bottom of the reservoirJiI is apipe 42 having branches 43, 44, 45, and 46 leading therefrom, each of said branches in turn leading-into bottom of =vapor izers i8, 59,25 and 2I respectively. The vaporizer I3 is, in the drawings, in the form of a jacket and has extending therethrough the -single pipe I5 which upon emerging from the vaporizer I8 as 34a forms the header pipe 40.

It is to be noted that only asmall amount of space is contained in the'vaporizer I81as compared to the other vaporizers. Extending through the vaporizer I9 are theitwo ducts :23 and 24 (but which may be more if desired) lwhich emerge from the vaporizer I9 as vapor Vducts35a-and 35 to connect with the header pipe4. Vaporizer 25 has a duct 41 with very thick walls- 48 of iron or other slow conducting substance, the duct .41 connecting with inlet duct 25 and return vaporcondensate duct 31 which in turn connects with header pipe 45. Vaporizer 2I has ductsl49..and 5B (but which may be more) with thick walls 5| of iron or other slow'conducting'substance These ducts 49 and 50 connect with inlet ducts 25 and 21, respectively, and-outlet ducts'38 and 35 which in turn connect withheader pipe 4B. The vapor ducts 41,49 and-" not only-haveawalls through duct 6 I.

that are much thicker than the walls of pipe I6, 23 and 24 in the vaporizers I8 and I9, but the pipes I6, 23 and 24 may be of the thinnest material consistent with tightness and mechanical strength so as to make possible the most rapid interchange of heat from the chemical vapor to the oil and oil-gas. Just before the branches 43 and 44 is placed a partial check valve 52, and just before branches 45 and 46 is placed a similar partial check valve 53. Figure 3 shows a horii Aor tting 54a to protect the system against excessive pressure. Leading from the vapor dryer I1 is a pipe 55 which in turn leads to diluting valve 56 at pipe connection 6I. Valve 56 is supported by clamp 51 and has-a nozzle 58 which is similar to the nozzle of an ordinary gas-cock on a gas stove, this nozzle may connect to any -suitable-deviceffor ymixing-gas and air such'as -in a Bunsen burner or on an ordinary stove or range. In pipe 55 is a constricted passage12 so constructed that it will only pass the maximum of oil-gas for which the apparatus -is designed and thus serves to prevent dampinglofheat of the vaporizers byoverload. rIlhe entire system comprising thel chemicallboiler, duct I6, return header 41) and yall intermediate vdigressions, ducts, ttings, etc. are to-be made tight and with no openings tofeither liquid or gasses or to the outside air as ,it is the -intention -to use the chemical over and over again Without wastage. All parts subject to heat radiation other than through heat interchangers and vapor dryers are to be thoroughly heat insulated Wherever practicable Figure 4 shows a vertical section of to do so. partial check valve 34 which is so designed-With Ya Asmall opening in the closer that it permits the free upward flow of gas or liquid -but a very slow-return This is the same with 32, 33,and also 35. As shown in Figure 5 the inside of the valve 56 is machined out concentrically, so as to receive a valve-core 60, as shown in Fig. 7,- which fits the valve intimately where the valve-ports 66, and 61 are located. IThe inner section of -the valvecore is machined out sucient tovpermit "-1 gasseswhich pass through any of the ports to enter a common chamber and so mix.-

'The'oil-gas produced from the apparatus is so Yrich inv heat units that it cannot be used eiiiciently `if taken at the same pressure as'fuel gas. It must vbediluted to approximately'the same heat value per cubicfoot-as fuel gas. This'isaccomplished v by the diluting valve y'shown inFigure 5. r'Rich oilfgasis brought from pipe 55 (FigL l) to valve Air, or a lean vor inertgas or mixture of gases or even steam, under approximately the vsame temperature andpressure, brought to theYother-fittingl of the diluting From the point of 4heating untovandincluding the 'diluting valve the entire system is 4thoroughly lheat'insulated. Yoke 52isxed to the stem 63 of the core 6I). A11 eccentric or cam-65,

Vas shown in Figures 'f8 and 9, is connected -to the yoke 62 to bring the core 60 which has passagesiinto alignment with passages 61. These passages are spaced along a common normal vcircle of the ligure formed by the inside surface of :the diluting valve 56 and are of the same diameter. .The object being to give a fixedlnever variable). proportion of rich gas and diluting gas at .any opening of the ports. The volume only ofthe mixture varies with the opening-the proportion remains the same. TheA gas from the lowerport 1 passes in the chamber formed by the coreII) and `mixes with the incoming gasses from the upper ports.A This mixture passes down through the The nozzle 58 is attached tothe joint and is shaped to avoid the formationof a pocket which couldcatch condensation. The area of the opening in the nozzle 58 may be changed soA as to have a larger or smaller opening but under no conditions would the cross-sectional f opening ofthe nozzle 58 be less in area-than the `combined effective areas of the ports when in nearest alignment.

. Interchange of eccentric 65 for one of greater -be used from the Very smallest use, such as -simmering flame under a coffee percolator to a maxi- -mum as used in the largest hotel or restaurant gas-ranges.

The onlychange necessary would be to change the nozzle 58 and theeccentric 65 to correspond.'v A coil spring 68 holds the core 60 in gas-tight contact with the body 58.

As actually operated, the reservoir 4|, having therein the liquid to be vaporized (hydro-carbon oil) and this liquid having descended through pipe 42 through the various branches 43, 44, 45 and 46 and entered the vaporizers I8, I9, 20 and 2| to a height commensurate with the height of the reservoir 4| and the volume of the liquid contained therein, and other laws of nature that cover such conditions, -there will be a substantial amount of hydro-carbon liquid in the various vaporizers.

A chemical, such as diphenyl-oxide, having a boiling point above that of water but lower than the cracking point of the hydro-carbon is placed in the boiler I4, and a source of heat I5, which may be either gas burner or an electric heating element, or any other suitable heating device, is operated to heat the chemical in the boiler. As the chemical becomes heated vapor from the chemical rises in duct I6 and enters a vapor dryer |1 and continues through the vapor dryer I1, passing freely through ducts 22, 23, 24, 41, 49 and 50 which lead from ducts I6, which in turn passes through vaporizer I8 to the header pipe 40 and then back to the boiler I4. Return ducts 35a, 36, 31, 38, and 39 leading from ducts 23, 24, 41, 49, 5l) after passing through their respective vaporizers also connect with header pipe 40 and return condenser chemical vapor to the boiler I4.

In order to prevent undue pressure on the chemical boiler system or undue temperature due to excessive pressure, which might cause the genera-ted gas to crack or change chemically, a pressurestat 13 is inserted in the boiler system. When the pressure of the chemical in the boiler system reaches a predetermined point the pressurestat operates to temporarily discontinue or reduce the heating action of the boiler heater. When the pressure drops to another pre-determined point the device operates to recommence or increase the heating action under the boiler. It is to be `carefullymoted that the vapor from the chemical boiler |.4fwi1l be on the inside ofthe hydro-carbon fuel andyas the vaporfpasses through the ducts inthe vaporizers, heat will be given olf through --the walls :ofthe ducts and the vapor chambers,

-thus heating the hydro-carbon fuel. It is also to be carefullynoted thatheat from 'vapor from chemical boileris. most intense athighest point .'ofygasf-d'ryer I1 and thatvaporizing of the-fuel from reservoir 4I is done in the v'vaporizers from the top downward. Also it is to be noted" that due tothe pitch ofithe ducts from the chemical boiler from the point where the rst condensation may commence, that is atthe top` of the gasdryer, the condensed chemical must pass by gravity down into andit must build up slightly in ducts 3441; 35a, 36, 31,3,8,'and 39 and form a top level above that of the liquid chemical in the boiler I4 and thusby hydrostatic pressure force vapor from boiler I4 upward throughv pipe vIt. and likewise condensed liquid through header 4I) into boiler V I4 at the bottom. Since it ishighly desirable,

under certain circumstances, to obtain a supply of gas-immediately, the duct I 6 passing through vaporizer I8-,.ha s thin walls` and may beof the thinnest material consistent with tightness and mechanical strength, so as to induce rapid transfer of heat. v l

The vaporizer I8 likewise has a small capacity of volume s o `that the heat passing through the walls Aof the duct I6, will rapidly permeate the hydrofcarbon fuel in the vaporizer I8 and quickly reduce the fuel to a gaseous state. Vaporizer I9 is likewise designed to generate gas quickly and has practically the same construction as I8 except that it contains a multiplicity of thin-walled ducts 23 and 24 and has greater cubical content than vaporizer 8. Instead of having thin walls of quick conducting material the walls 48 oi' vapor duct41 in vaporizer 20 are of thick material, such as iron, and massive so as to Vafford a reservoir for storing up heat and a slow conductivity so that it may be arranged to give up its heat slowly on demand. The same is true of vaporizing ducts 49 and 50 in vaporizer 2| which indicates a vaporizer having a multiplicity of ducts. The most important function of the heavy walls of the ducts in and in 2| is to store up heat and to supply heat for gas during outings in which the heating effect under the chemical boiler is either reduced or else cut oil. entirely. Also in that interval between the application of heat to the chemical boiler I4 and the time when the vapor applies its heat to the thin walled vaporizers I8 and I9 the heavy walled tubes will give out part of their heat to vaporize the fuel. The eiicient heat insulation mentioned will reduce radiation losses to a minimum. After the hydro-carbon fuel has become sufficiently heated to assume the gaseous state, the gas will ascend in the several ducts, pass through dryer I1, where it attains a temperature approximately that of vapor from chemical boiler I4, thence out through pipe 55, through constricted passage 12 and to opening 6| in diluting valve 56. There is one diluting valve for each gas jet. Operation of handle 1| (see Figure 8) which rotates in a support 51a which is rigid with 51 (see Figure 6) and which rotates an eccentric within yoke 62 causes valve-stem 63 to rotate bringing ports 66 in valve core 60 in proportionate alignment with ports 61 in valve-body 56.

By this simple mechanism an exceedingly fine tained without using unusual care in moving the handle' il. The v.object being .to simulate :as

V:nearly as possible the :movement of :an ordinary fuel-gas cock on an .ordinary gas range.

It is obvious that my Yinvention may be used 'in 'other forms 'than .those'used'to illustrate it in :my drawings, vand :I `do 'not intend to limit myself -out c'rackingfcomprising a plurality of vaporzers, veach -vaporizerhaving fuel and. vapor compart- -ments,'the fuel compartment *in each vaporizer surrounding each vapor compartment, the outer wall of said vapor compartment and the inner Wall of said fuel compartment forming'a common wall conducting heat fromv said vapor te said fuel, the 'common Wall of one lof said vaporiizers being lthinner and of better'conductive 'ma- .terial than .the material lforming the common I'Wall of 'the othervaporizers.

An 'apparatus for vaporizing'liquid'fuel without cracking, comprising a liquid fuel tank, 'a

plurality of vaporizers, each of said lvaporizers @having fuel and `vapor compartments separated by a Wall of heat conducting material valve cont-.trolled means #connecting said tank to the fuel 4compartmentin each vapor-iger, the common wall 'o'fone of said vaporizers beingthinner fand of "better heat conducting material than -the comrmonwall of others f'saidvaporizers.

' I3. vAn apparatus for vapori'zing liquid fuel without .cracking-comprising a fuel tank and a-'vapcr producing .-rcceptaele, a .plurality lof vaporizers,

Veach vvaporizer having fuel and Vvapor compartments separated by a fcommon wall of `heat conv5 fducting material, means for connecting said fuel :and vapor compartments `to the fuel tank and 'vapor Yproducing receptacle, respectively, 'the Yfcommon "wall 'of one of -said vaporizers being formed of 'material yof 'g1-eater heat conductivity'frloi than lthe common. Wall in Vthe other vaporizers,

V:and :means for returning the 'vapor in condensed form from alllo'f the said vapor compartments'to, r-the l.vapor producing receptacle, and means :for conveying gas vfrom al1 ofthe fuel compartments-R5 sin said Vaporizers.

.4. An apparatus 'for vaporizing liquid fuel .Witti- `eut cracking, .comprising a fuel tank and a vapor -producing receptacle, a plurality vof vaporizers,

'each `vaperizer yhaving fuel andlvapor lcovrlpmi-02X) mentslseparatedby a common wall vof heatconducting material, means yfor connecting'saidfuel and vapor compartments to .the fuel :tank and 'vapor producing receptacle, respectively, 'the y'commonWall o'f oneof said Vaporizers'being thin- Q5 ffner and 'composed of material `of greater heat feonductivitylthan. the corresponding wall in the other fvaporizers, :means for returning the vapor in :condensed lform from all of Vsaidrvapor'com- `partmentsto the vapor 'producing receptaclepand'm) means for conveying gas from the fuelcompartments fof :said 'vaporizers NORMAN'FRANCIS PliAII.l 

